Clutch for artificial arms



M y 8, 1954- s. w. ALDERSON 2,678,709.

CLUTCH FOR ARTIFICIAL ARMS v Original Filed July 10, 1948 6 Sheets-Sheet 1 N 9 LL Q \o 3 2 LI- INVENTOR Samuel lllfl'ider-son.

May 18, I954 s. w. ALDERSON 2,678,709.

CLUTCH FOR ARTIFICIAL ARMS Original Filed July 10, 1948 e Sheets-Shet 2 x? FEE S: 20 :28; 5: l I l l lull.

INVENTOR Samuel W fllderson Acm May 18, 1954 s. w. ALDERSON CLUTCH FOR ARTIFICIAL ARMS Original Filed July 10, 1.948

6 Sheets-Sheet 3 mokoudn Iotju muIu-rn-G I uZmn ZOE-(20ml uZtO xuJm Alvi \N\ v v.

May 18, 1954 s. w. ALDERSON CLUTCH FOR ARTIFICIAL ARMS Original Filed July 10, 1948' '6 Sheets-Sheet 4 P02. Bow -u INVENTOR Samurai Wflidenson.

2 AGENT WEIWUE mbE L 25:52 whv y 13, 1954 s. w. ALDERSON CLUTCH FOR ARTIFICIAL ARMS Original Filed July 10, 1948 6 Sheets-Sheet 6 wmx INVENTOR JamzzeZll/fllderson AGENT Patented May 18, 1954 UNITED orrics Original application July 10, 1948, Serial No. 38,018. Divided and this application May 17, 1951, Serial No. 226,882

7 Claims. 1

The present invention relates to clutch mechanism employed in electrically operated artificial arms.

This application relates to subject matter found in a copending application, Ser. No. 38,018, filed July 10, 1948, now Patent Number 2,580,987, issued January 1, 1952, of which this application is a division. Reference is also made to Patent 2,592,842, issued April 15, 1952, and Patent 2,640,994 issued June 9, 1953, both divisions of the said application serial Number 38,018, filed July 10, 1948, as well as Patent 2,580,987 for a full disclosure of the present invention and the manner of its employment.

An object of the invention is to provide an electrical arm capable of a plurality of movements in which any one of them may be selectively performed without disturbing or otherwise affecting the others.

Another object of the invention is to provide an electrically driven arm of this type wherein the motive force by means of which the electrical arm is powered consists of a relatively small lightweight compact motor which is wholly contained within the forearm section of the arm in the elbow region thereof and which in the assembled arm is completely concealed from view.

Another and important object of the invention is to provide a novel type of selective clutch mechanism likewise wholly contained within the forearm section for selectively controlling by a common drive from the motor the four independent types of arm movement briefly outlined above.

A still further object of the invention is to provide an electrical arm of this type in which the selective clutch mechanism consists of a selfcontained unit capable of being installed in or removed from the arm with facility as a unit and which, when installed, is mounted in the forearm section by a resilient floating connection, thereby reducing vibration and protecting the same from possible shock and, as a consequence, contributing toward the elimination of noise.

Yet another object of the invention is to provide an electrical arm capable of the four independent types of motions set forth above in which the motions may be reversed at the will of the amputee by the simple expedient of reversing the direction of rotation of the motor shaft while maintaining any one of the selected types of control in effect.

Another object of the invention is to provide an artificial arm including a selective clutch mecha nism of the type briefly outlined above in which selection of the particular type of motion desired may be made under the control of a series of contacts adapted to be operated by relative movement oi an anatomical part of the body, as for example, the big and little toes of one foot of the amputee.

The selective clutch mechanism referred to above is reversible in all four phases of its operation. An electrical control means for selectively actuating the clutch mechanism is provided under the control of the amputee. A novel form of switch mechanism is located in one of the shoes of the user and may be manipulated by the toes for selectively operating the clutch mechanism to obtain the desired motions of the component parts of the arm. In the case of an amputee having a sufficiently long above-the-elbow stump including an active biceps, the stump section has associated therewith a stump switch adapted to be operated by a partial tensing of the stump biceps to provide a master control capable of energizing or deenergizing the motor so that motion or no motion of the arm is effected, as desired. The stump switch is also used to control the direction of motion of the component parts of the arm after a selection of the type of motion desired has been made by the electrical foot controls.

In the drawings;

Fig. 1 is a perspective view of the electrical arm proper showing the same being worn by a rightarm amputee having an upperarm stump of substantial length and also showing the harness by means of which the arm is retained on the body of the user.

Fig. 2 is an enlarged fragmentary view of a portion of the upper arm section of the electrical arm illustrating the manner in which a stump switch employed in connection with the invention may be manipulated by the biceps muscle of the amputee.

Fig. 3 is a circuit diagram of the electrical connections for the arm.

Fig. 4 is a fragmentary side elevational view of the electrical arm showing the jointed sections thereof.

Fig. 5 is a fragmentary top plan view of the structure shown in Fig. 4 and including dotted line illustrations of internal structure of the arm mechanism, together with suitable legends therefor.

Fig. 6 is a schematic view of the various drive mechanisms and clutches employed in connection with the electrical arm illustrating the manner in which the desired arm movements may be attained upon proper clutch selection.

7 is a schematic end view of the selective clutch mechanism employed in connection with the present invention with the clutch centers in their proper positions.

Fig. 8 is a fragmentary enlarged detailed secticnal view taken longitudinally through the elbow joint structure and a portion of the forearm section proper showing the electric motor, the main driving shaft and a portion of the selecting devices for the selective clutch mechanism employed in connection with the electrical arm.

Fig. 9 is a sectional view taken substantially along the .line 9-52.01 Fig. 8.

Fig. .10 is a sectional view taken substantially along the line I8l S of Fig. 8.

Fig. 11 is a sectional view taken substantially along the line II-II of Fig. and showing in detail a radial clutch actuating arm'employedin connection with the present invention.

Fig. 12 is a sectional view taken substantially along the line Il'I 1 of Fig.5.

Fig. 13 is a side elevational viewof the structure shown in Fig. 12 with the casing broken away. This view shows the hand .and wrist pronation drive mechanism.

Fig..14 is adetailed sectional view of one of the clutch units proper employed in connection with thepresentinvention.

Brief description Referring now to the drawings in detailand in nected as at'22 to the upper arm structure Ill.

The wristassembly I4.is coaxial with the forearm section I8 and ispivotally connected to the free end of the latter for rotational movements in either direction about the common axis of the "two sections by'means .of a pronation joint struc- *ture'24'whichis common to the two sections.

The wrist assembly I4 and handassembly I5 are pivotally connected together by a hand flexion joint'26. Thehand assembly It includes a palm portion 2S and four independently movable digit or finger sections including a rigid thumb pivotally secured as at 32 to the palm portion 28, a. multiply articulated little finger 34, a multiply articulated ring finger .36 and separately'molded index and middle fingers '38 and 40 respectively, which are notable in unison relative to the palm portion28. As shown in Fig. 5, the index, middle, ring and little fingers are pivoted for swinging movement relative to the palm portion .28 on a :gmmon finger, pivot in the form of a pintle pin The electrical arm is powered by .means of a small, compact, .portablebattery unit B (Fig. 3) adapted to'be conveniently carried inthe trousers pocket 68, preferably on the same .side as the amputation. The control of the various movements of the electrical-arm is effected by means of a series of electrical contacts containedin one ofthe-shoes of theuser, as for-example, the right shoe Ill, and also under the control ,of a stump switch assembly/'12 (Figs. 1,2, and 3). Thecontrolcontacts-in the shoe are utilized for thepurpose of effecting the selected type ofmovement for the various parts ofthe arm, while the stump switch is employed to initiate the selected type of movement as well "as for selecting a forward or reverse movement, all in a manner that will be made clear presently.

:The motor, motor drive and supporting structure therefor "The'motor, outlined in Fig. 5, which is of the direct current, reversible, permanent magnet type, is supported within the elbow joint strucbase casting 2| which is of box-like configuration and which .has .an open .upper end adapted to "be closed by means 0f 2. cover plate 23. The forward end of the elbow joint structure is pro- .vided with a rectangular channel portion 18 affording an external groove adapted to receive therein arsuitable sealing gasket 82 (Fig. 8) which may .be .formed of soft rubber or the like, and which affords a seal for the forearm section proper I8 whenthe cover plates 52 and 54 are in position.

The motor M "is in the form of a substantially rectangular box-like casing which is bolted or otherwise secured as at 86 to a gear reduction assembly 88, likewise of box-like configuration, and which is mounted by'means of a floating connection-fromthecasting 2|. The floating connection just referred to includes an upstanding bracket'which is secured to the end wall 92 of the-casting '2'! by meansof through-bolts 94 and which is spaced therefrom by meansof spacing collars '86. -A plurality 'of attachment plates 98 are secured-to the-bracket by means of studs I00 and these attachment plates 98 are fastened to respective supporting pads I02 which may be formed-cf resilientmaterial such as rubber. The supporting pads I62 are fastened to respective attachment bosses I84 carried on the casing of the gear reduction assembly -'88 and thus the gear ieduction "device and the motor are yieldingly supported from the casting 21 with the solid resilient pads I02 constituting the sole supporting =meansfor the motor andgearreduction assembly.

Ihe gear reduction device 88 is provided with r an output-shaft I96 which is connected through -a resilient coupling I08 to a floating shaft IIO which inturnis-connected through a second resilientcoupling to a shaft I I4, which may be regarded as the main drive shaft leading to the various gear train mechanisms employed for effecting thedesired movements of the component parts of "the electrical arm.

The selective clutch assembly .ReferringnowtoEigs. 6, 7, 8, 9, 12, Band 14. the selective clutch mechanism is designated in its :entirety at I28 in Figs. 12 and 13, and is a unitary self-contained assembly which is mounted .withinthe forearm section proper .I'B by means of :a .fioating connection. The drive shaft II 4 constitutes the input drive for this clutch as- .sembly.

The clutch assembly involves in its general organization arigid but floating frame-like structure .I22 including-a front end plate I24 (Figs. :Gand 71-3) ,a-media-l plate I26 and a rear end plate I28 (Fig. 10). The plates I24 and i28 are connected together by means of spacing members 'I.30.and the medial plate I26 and end plate I28 are connected together by means of spacing members 132. The end plate I24 is provided with a 513811 of .latera'lly extending ears I34 which are supported from a pair of longitudinally extending parallel frame members 136 and I38 integrally formed with an end piece in the form of a ring I 39 constituting a art of the forearm framework 50. The frame members I36 and I 38 are generally of channel-shaped construction to lend strength to the structure and they may be integrally cast with one element of the pronation joint structure 24 at the front of the forearm section *proper I8.

The clutch mechanism proper I20 includes a series of four-clutch elements I 44, I46, I48 and I50. The clutch element I44 is adapted to go into operation to eifect the elbow drive or, in other words, to attain elbow flexion. The clutch I46 is adapted to go into operation to effect hand and wrist pronation at the pronation joint 2d. The clutch M8 is adapted to go into operation to effect opening and closing movements of the index and ring finger assembly relative to the thumb. The clutch 50 is adapted to go into operation to effect hand fiexion, all in a manner that will presently be set forth.

The clutch elements I54, I45, I48 and I are substantially identical in construction and are mounted in the floating clutch assembly :22 at substantially equally spaced points arranged about a common center and these elements 00-- cupy the same transverse plane.

Each clutch element includes a supporting shaft I52 which is rotatably journaled in the front and medial plates E24 and I26. The clutch elements are of the reverse acting type, that is to say, the driven element of the clutch may coast with the driving element thereof to eifect rotation of the clutch elements in opposite directions to reverse whichever character of motion of the electrical arm is selected. A driven element is mounted upon and secured to the shaft I52. This element is in the form of a circular disc having outwardly projecting clutch teeth I56 on one side thereof. These teeth oppose a series of similar teeth provided on the driving 1 element 558 of the clutch. The driving element is similar in configuration to the driven element and is rotatably mounted on the shaft I52 in close proximity to the driven element. Each driving element includes an integrally formed gear IfiIl and all four of the gears I are in constant mesh with an idler gear I62 mounted on a shaft IE3 rotatably journaled in the front and medial plates 524, I26. The gear I60, which is integrally formed with the clutch M8 and which controls the opening and closing movements of the fingers, meshes with a driving gear I55 mounted on the drive shaft H4 and thus when the motor is energized and the drive shaft lid is rotated, a drive is transmitted from the gear 565 to the gear I50 of the clutch M3 and from thence through the idler gear I62 to all of the clutch elements I58 so that these elements rotate in unison.

When the arm is at rest and no relative motion between any of the component parts thereof is contemplated, the drive shaft IIfl remains stationary due to lack of energization of the motor M. As soon as a selected movement 01 the arm is contemplated, the motor M is energized by 'ieans of a suitable control to be described subsequently and the drive shaft I I4 commences to rotate in the selected direction, thus causing all four of the driving gears I60, and consequently all four of the driving elements I58, to rotate in unison. Until one of the clutches I44, I46, I48 or !50, as the case may be, is thrown into meshing engagement no movement of any parts of the arm will result and when the selected clutch is finally engaged one of the four types of move ment, namely, opening and closing of the fingers, hand and wrist pronation, hand fieXion or elbow fiexion, is attained. In Fig. 6 the various drives for effecting these motions is schematically shown.

Each shaft 52 is slidably, as well as rotatably, mounted in the front and medial plates I24, I26

and the limited amount of sliding movement of which the shaft is capable is determined by the provision of a collar ISI' which is secured on. the

shaft and. by the position of the driven clutch element I54. In the normal open or inoperative position of the clutch, the clutch element I50 abuts against a supporting bushing I55 which is anchored in the medial plate I26. In the closed or operative position of the clutch, the collar I61 abuts against this bushing. The clutch elements i555 and I58 are maintained separated by means of a spring I64 (Fig. 14). Each shaft I52 projects completely through the medial plate I26 rearwardly thereof and has mounted thereon and secured thereto an elongated sleeve I10 which is threaded as at I12 along a major portion of its length and which is adapted to receive thereon an anti-friction bearing assembly in the form of a retaining nut I'M in which there is disposed a hardened steel ball Ilii designed for cooperation with a clutch actuating finger I18 (see Figs. 10 and 11 carried on a selector shaft I80. A coil spring is disposed within the sleeve I10 and bears at one end against the ball I'i'ii and at theother end against the end of the shaft I52 to transmit any thrust exerted upon the ball I76 to the shaft 52 for clutch engaging purposes.

The shaft I80 (Figs. 8, l0 and 11) is capable of limited slidable movement in an axial direction and, toward this end, one end thereof is rotatably and slidably disposed in the medial plate I25 of the floating framework other end thereof is slidably mounted in a bushing I32 which is pressed into the bore of the sleeve portion I84 of a clutch element 80 forming one part of a clutch assembly H08. The sleeve portion I8 has mounted thereon a gear and a set screw I92 extends through the hub portion of the gear I90 and through the sleeve I84 and bears against the bushing I82 to retain the same in fixed position relative to the gear I90. The sleeve portion I85 of the clutch element I86 is journal-ed in a sleeve I96 which is fitted within a hub or boss I96 formed in the end plate I28 of the framework I22.

The clutch assembly 588 includes a second clutch part I93 which is pinned as at 200 to the shaft I30 and which, as a consequence, is rotatable and axially movable therewith. A spoollike sleeve 202 surrounds the shaft I80 and is concentric with the clutch part I98. This spoollike sleeve 202 is provided with an out-turned flange 20d which serves to retain an insulating ring 205 in position on the clutch part 598. A spring 263 surrounds the shaft I80 and bears at one end against a collar 2H) and at the other end against the clutch part I98 and serves to normally maintain the clutch assembly I88 engaged.

A friction member 589 is secured to the plate iZfi and is provided with a friction surface ISI designed for cooperation with a friction surface 5% carried on a friction disc :95 secured as at iii"! to the shaft 583. Inasmuch as the spring 208 normally urges the ltd to its extreme righthand position, as shown in Fig. 10, the friction disc tab is normally maintained out of engagement with the fraction member iBll.

A brush 2E2 forming part of distributor assembly 2 id (see also Fig. 3)-

mounted in the insulating ring 2&6 and is provided with a short finger 2 2 5 and a long finger 2 it the former bearing against an inner distributor ring 220 and the latter bearing against a series of outer distributor segments 222 carried in a diSt-l'lblltOr block 2124 which is supported by means of spacing members 226 from the end plate 528.

. The collar 2w is provided with a pairof trun- I22 and the carried by the rearend plate 528. "The gear nions 230 which projectiinto slots'2-32 fomnecljina yoke 234 whichispivotedas at 236 to a bracket 238 which is bolted or otherwise secured as .at 240 to the plate I26. The=other end of-theyoke 2-34 is provided witha pair-ofislots 242 intowhich there extend-a pair of trunnions .246 carried on the core element 2:36 of a clutch magnetCM bolted-or otherwise securedasat .245 to the plate 526.

From the above description of parts it will be seen that upon energization of the clutchmagnet CM'its core 246 will be attractedthus swinging the yoke member 2.3:. in a clockwise direction about its pivotal axis 235,.so as to cause the trunnions 23E on the collar etc and, consequently, the collar itself, to be moved axially to the left as viewed in Figs. 8 and 10. Such movement of the collar 2H} causes the shaft I86 to be moved axially, thus removing the driven element 198 of the clutch assembly 138 from engagementwith the driving element H25 thereof and causing the friction surfaces is! and 83 to become engaged, thus terminating further rotation of the shaft I 80 so that the selector finger ilS ceases its revo lution about the axis of the shaft fiBfl.

Referring now to Fig. 8, the gear i1 meshes with a smaller gear 251 mounted on a stud 252 250 is integrally formed with a larger gear 253 and this latter gear meshes with a smaller gear 254 mounted on the drive shaft l i l. As will be pointed out hereinafter, upon closure of the various electrical contacts employed in connection with the operation of the electrical arm, the motor M will be energmed and the drive shaft I :4 caused to rotate, thus causing the shaft I30 to be rotated and causing the selector finger 5'78 to revolve about the axis of the shaft i 89. Immediately after the motor becomes energized, selection of a predetermined type ofmotion is made and the selector finger FEB moves into register with one of the clutch assemblies 144, M6, M8 or I58, as the case may be, after which, due "to certain relay instrumentalities employed in connection with the present invention, the clutch magnet CM becomes energized and, as a consequence, the shaft its is caused to be moved :to the left, as viewed in Fig. '10, thus carrying with it theselector finger H8 which bears against the hardened steel ball l 76 of the-selected clutch assem- 'bly to move the clutch element let into engagement with the constantly rotating clutch-element i58.

The electrical instrumentalities THE POWER SUPPLY The electrical instrumentalities associated with the electrical arm are the previously mentioned motor M which is supported in the elbow joint structure 23 by means of a floating connection; the distributor 2 I4 contained in the forearm section proper i8 near the rear end thereof; the clutch selector magnet CM likewise contained within the forearm section proper 13; the battery unit B which is adapted to be maintained within the right-hand trousers pocket of the amputee; a pair of relay magnets R! and R2 together with their operating contacts which may conveniently be supported from the hip plate 5%; the stump switch 12 which is supported on a bracket 564 mounted on the stump-receiving socket 48 of the upper arm structure it; a pair of toe contacts Sb and S1 in one of the shoes of the user, to-

- gether with electrical wiring which is convenient- 1y distributed within the arm structure and in and about the body of the amputee in such a mamier as to most effectively perform the re- 8 quired functions,:all in a manner that will beset forth when the electrical circuits for the arm are described.

THE STUMP swrrcn Referring now to Figs. 1, 2 and 3, the stump switch assembly 72 is suitably mounted on the bracket 564 which in turn is attached to the stump-receiving socket 48 on the inner side of the upper arm stump between the stum and the body of the amputee. Thestump switch assembly l2 projects upwardly in front of an opening 575 provided in the side-of the stump-receiving socket for the purpose of allowing the amputee to project his-stump biceps through the opening andagainst a'control fingeriiil which is pivoted as at 579 above the opening 515 and which depends downwardly in front :of the opening to selectively manipulate "a series of contacts associated with the stump switch. [L11 operating finger 2-38: is associated with the switch assembly" and is positioned in-the path of movement of the control finger 571.

In Fig. 3, it will be seen'that three sets of contacts labeled 1, 2 and '3 are associated with the stump switch assembly 12. Contact 1 is normally maintained open but is adapted to become immediately closed upon any projection of the stump biceps whatsoever. Contacts -2 and 3am each of the single pole double throw type which normally assume the position-shown in Fig. 3.

In the full line position of the stump biceps the contacts 1 are open and the contacts 2 and 3 ssume their normal positions. In the dotted line position of the biceps the contacts 1 become closed while the contacts 2 and 3 still remain in their normal position. With the biceps in its broken line position the contacts 1 remain closed, while the contacts 2 and 3 both become reversed. As will be pointed out when the circuit diagram of Fig. 3 is explained, the contacts 1 when closed effect energization of a circuit leading through the motor M to energize the motor and cause the same to operate in one direction. With the contacts 1 closed and the contacts 2 and 3 reversed, the motor circuit will still be energized but with current of reverse polarity, thus causing the motor to run in the opposite direction and reverse the character of movement selected for the artificial arm by the use of a pair of toe switches contained in the shoe of the amputee, whose nature and function will be described subsequently.

The electrical circuits 'lHE MOTOR CIRCUIT Referring now to Fig. 3 wherein the circuit diagram for the electrical arm is shown, initial manipulation of the stump switch l2 by a partial extension of the stump biceps serves'to close'the 1 contacts of this switch while allowing the 2 .and 3 contacts thereof to maintain their normal positions as shown. Thus a circuit will be established from the positive side of the battery B through a master switch Sm, 1 contacts of the CONTACT SELECTION 1 Relay Operation Type of Control Toe Contact Operation l Finger i\lanipulation so open, 81 open $233323: l'l'figliglnfilid \l rist Pronaopen SZ closed glegngirzilgcd.

. n R 1 Elbow Flenon Sb closed, Sl open"... (L Hand Flexion Sb closoi, SZ closed. Egg .2223:

HAND AND WRIST PRONATION For effecting hand and wrist pronation in either direction the motor circuit remains the same and a description thereof is believed to be unnecessary. To effect hand and wrist pronation the little toe is depressed, thus closing the contact S2 and establishing a circuit from the battery B through the master switch Sm, 1 contacts of the switch 72, 2 contacts (normal), wires a, b, o, p, magnet R2, wire 0, contact 81 plate 568', wires r, 1!, f, 3 contacts of the switch 12 (normal), and wire 9, to the source. Energization of the magnet R2 causes reversal of tr e 2 contacts thereof thus connecting the hand and wrist pronation segment 222 to the negative side of the battery through a circuit which exists from this segment through wire s, 1 contacts of the magnet R2 (reversed), 1 contacts of the magent RI (normal), wires is, l, f, 3 contacts of the switch 12, and wire 9 to the battery B. It is obvious that when the direction of rotation of the motor shaft is reversed, hand and wrist pronation in the opposite direction will occur.

ELBOW FLEXION For elbow flexion the big toe is depressed to close the contact Sb and establish a circuit through the magnet R! leading from the battery B through the master switch Sm, 1 contacts of the switch 72, 2 contacts (normal), wires a, b, o, t, magnet Rl, wire it, contact Sb, wires 1', Z, 3 contacts of the switch l2 and wire 9 to the battery B. Obviously elbow flexion in either direction will involve the same circuit by a reversal of the motor M.

Upon energization of the magnet RI a circuit will exist from the elbow fiexion segment through wire 12, 2 contacts of the magnet R2 (normal), 1 contacts of the magnet RE (reversed), wires k, Z, 3 contacts of the switch 12, and wire g to the battery.

HAND FLEXION For hand fiexion purposes, both the big toe and the little toe are depressed to close the contacts Sb and S1 and energize both the magnets Bi and R2 through circuits previously described. Upon energization of these two magnets, a potential circuit will exist from the hand fiexion segment 222 through wire 10, 2 contacts of the magnet R2 (reversed), 1 contacts of the magnet Rl (reversed), wires k, 2, f, 3 contacts of the switch 12 (normal), wire g to the battery. Reversal of the hand fiexion operation is, of course, obtained 10 through the same circuit with the polarity of the motor M reversed.

What is claimed is:

1. In a selective clutch mechanism of the character described, a plurality of pairs of coacting clutch elements each including a rotatable driving element and a rotatable driven element, means for selectively rotating said driving elements in unison in either direction, means normally maintaining the clutch elements of each pair disengaged, clutch-engaging means common to said clutch pairs, means for moving said clutch-engaging means into register with said clutch pairs successively and repeatedly, said clutch-engaging means also being shiftable from a position of registry with each clutch pair into direct engagement With one of the elements thereof to move the latter into engagement with the other element thereof and effect movement of the driven element in the direction of movement of the driving element, a solenoid operable upon energization thereof to shift said clutch-engaging means into clutch-engaging position, a distributor assembly including a distributor contact for each clutch pair, means for sensing said contacts successively in timed sequential relation to the successive registry between said clutch-engaging means and the clutch pairs,

- means for selectively applying electric current to said contacts, and means operable upon sensing of an energized contact to energize said solenoid to cause engagement of the selected clutch pair.

2. In a selective clutch mechanism of the character described, a plurality of pairs of coacting clutch elements each including a driving element and a driven element mounted for rotation about a common axis, the axes of said pairs being equally spaced about a common axis, means for rotating said driving element in unison, means normally maintaining the clutch elements of each pair disengaged, a clutch operating finger mounted for rotation about said common axis to bring the same successively into register with said clutch pairs, means for rotating said finger, said finger also being shiftable axially when in register with a clutch pair to engage one of the elements thereof and move the same into engagement with the other element and effect movement of the driven element, a solenoid operable upon energization thereof to shift the finger into clutch engaging position, a distributor assembly including a distributor contact for each clutch pair, means for sensing said contacts successively and in timed sequential relation to the successive registry between the finger and clutch pairs, means for selectively applying energizing current to said contacts, and means operable upon sensing of an energized contact to energize said solenoid, shift said finger, and cause engagement of the selected clutch pair.

3. In a selective clutch mechanism of the character described, a plurality of pairs of coacting clutch elements each including a driving element and a driven element mounted for rotation about a common axis, the axes of said pairs being equally spaced about a common axis, means for rotating said driving element in unison, means normally maintaining the clutch elements of each pair disengaged, a clutch operating finger mounted for rotation about said common axis to bring the same successively into register with said clutch pairs, means for rotating said finger, said finger also being shiftable axially when in register with a clutch pair to engage the driven element thereof and move the same into engagement with the other element and effect movement of the latter element, a solenoid operable upon energization thereof to shift the finger into clutch engaging poistion, a distributor assembly including a distributor contact for each clutch pair, means for sensing said contacts successively and in timed sequential relation to the successive registry between the finger and clutch pairs, means for selectively applying energizing current to said contacts, and means operable upon sensing of an energized contact to energize said solenoid, shift said finger, and cause engagement of the selected clutch pair.

4. In a selective clutch mechanism of the character described, a plurality of pairs of coacting clutch elements each including a driving element and a driven element mounted for rotation about a common axis, the axes of said pairs being equally spaced about a common axis, means for selectively rotating said driving element in unison in either direction, means normally maintaining the clutch elements of each pair disengaged, a clutch operating finger mounted for rotation about said common axis to bring the same successively into register with said clutch pairs, means for rotating said finger, said finger also being shiftable axially when in register with a clutch pair to engage one of the elements thereof and move the same into engagement with the other element and eifect movement of the driven element in the direction of movement of the driving element, a solenoid operable upon energization thereof to shift the finger into clutch engaging position, a distributor assembly including a distributor contact for each clutch pair, means for sensing said contacts successively and in timed sequential relation to the successive registry between the finger and clutch pairs, means for selectively applying energizing current to said contacts, and means operable upon sensing of an energized contact to energize said solenoid, shift said finger, and cause engagement of the selected clutch pair.

5. In a selective clutch mechanism of the character described, a plurality of pairs of coacting clutch elements each including a driving element and a driven element mounted for rotation about a common axis, the axes of said pairs being equally spaced about a common axis, an electric motor, means operatively connecting the motor and driving elements for driving the latter in unison,

means normally maintaining the clutch elements of each pair disengaged, a clutch operating finger mounted for rotation about said common axis to bring the same successively into register with said clutch pairs, means operatively connecting the motor and finger for driving the latter, said finger also being shiftable axially when in register with a clutch pair to engage one of the elements thereof and move the same into engagement with the other element and efiect movement of the driven element, a solenoid operable upon energization thereof to shift the finger into clutch engaging position and at the same time to disengage its connection with the motor, a distributor assembly including a distributor contact for each clutch pair, means forsensing said contacts successively and in timed sequential relation to the successive registry between the finger and clutch pairs, means for selectively applying energizing current to said contacts, and means operable upon sensing of an energized contact to energize said solenoid, shift said finger, and cause engagement of the selected clutch pair.

6. In a selective clutch mechanism of the character described, a plurality of pairs of coacting clutch elements each including a driving element and a driven element mounted for rotation about a common axis, the axes of said pairs being equally spaced about a common axis, an electric motor, means operatively connecting the motor and driving elements for driving the latter in unison, means normally maintaining the clutch elements of ach pair disengaged, a clutch operating finger mounted for rotation about said common axis to bring the same successively into register with saidclutch pairs, means operatively connecting the motor and finger for driving the latter, said finger also being shiftable axially when in register with a clutch pair to engage one of the elements thereof and move the same into engagement with the other element and efiect movement of the driven element, a solenoid operable upon energization thereof to shift the finger into clutch engaging position and at the same time to disengage its connection with the motor, means operable upon shifting of said finger for applying a braking torque thereto to terminate rotation thereof about the common axis and to maintain the same in registry with a selected clutch pair, a distributor assembly including a distributor contact for each clutch pair, means for sensing said contacts successively and in timed sequential relation to the successive registry between the finger and clutch pairs, means for selectively applying energizing current to said contacts, and means operable upon sensing of an energized contact to energize said solenoid, shift said finger, and cause engagement of the selected clutch pair.

7. In a selective clutch mechanism of the character described, a plurality of pairs of coacting clutch elements each including a driving element and a driven element mounted for rotation about a common axis, the axes of said pairs being qually spaced about a common axis, a reversible electric motor, means operatively connecting the motor and driving elements for driving the latter in unison in either direction, means normally maintaining the clutch elements of each pair disengaged, a clutch operating finger mounted for rotation about said common axis to bring the same successively into register with said clutch pairs, means operatively connecting the motor and finger for driving the latter, said finger also being shiftable axially when in register with a clutch pair to engage one of the elements thereof and move the same into engagement with the other element and effect movement of the driven element in the direction of the driving element, a solenoid operable upon energization thereof to shift th finger into clutch engaging position and at the same time to disengage its connection with the motor, a distributor assembly including a distributor contact for each clutch pair, means for sensing said contacts successively and in timed sequential relation to the successive registry between the finger and clutch pairs, means for selectively applying energizing current to said contacts, and means operable upon sensing of an energized contact to energize said solenoid, shift said finger, and cause engagement of the selected clutch pair.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,846,687 Mentor Feb. 23, 1932 2,098,691 Neff Nov. 9, 1937 2,488,324 Pegard Nov. 15, 1949 

